Redis缓存
一.注解
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@EnableCaching 在SpringRedisApplication类中加添加,开启高速缓存.
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@Cacheable(value = “roleService”, key = “#roleId”)
在service实现类中的方法上添加,表示给某个方法开启缓存,
后面的key就是在返回值中拿到插入之后的数据,是在redis中的缓存中拿到的,
不用再查询数据库. -
@CachePut(value = “roleService”, key = “#roleInfo.roleId”),
在执行插入操作的时候,直接把插入的数据存到redis缓存中,查数据时,直接缓存中取数据. -
@CacheEvict(value = “roleService”, allEntries = true),
在执行删除操作的时候,会把缓存中的所有缓存清空. -
@GeneratedValue(strategy = GenerationType.IDENTITY),
给实体类属性id列设置为主键,自增长.
二.缓存具体实现(附加点赞demo)
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在SpringRedisApplication类中加上注解: @EnableCaching
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创建entity层,代码如下:
import javax.persistence.*; import java.io.Serializable; @Entity @Table(name = "role_info") public class RoleInfo implements Serializable { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long roleId; private String name; @Override public String toString() { return "RoleInfo{" + "roleId=" + roleId + ", name='" + name + '\'' + '}'; } public Long getRoleId() { return roleId; } public void setRoleId(Long roleId) { this.roleId = roleId; } public String getName() { return name; } public void setName(String name) { this.name = name; } } -
创建mapper层,代码如下:
import org.springframework.data.jpa.repository.JpaRepository; public interface RoleMapper extends JpaRepository<RoleInfo,Long> { } -
创建service层,代码如下:
public interface RoleService { List<RoleInfo> findAll(); RoleInfo findOne(Long l); RoleInfo addOne(RoleInfo roleInfo); Boolean delete(Long roleId); public boolean thumb(Long roleId); public Set<?> thumbList(); }service层实现类如下:
@Service public class RoleServiceImpl implements RoleService { @Autowired private RoleMapper mapper; @Resource private RedisTemplate<Object, Object> redisTemplate; @Cacheable(value = "roleService") @Override public List<RoleInfo> findAll() { System.out.println("RoleServiceImpl.findAll"); List<RoleInfo> all = this.mapper.findAll(); return all; } @Cacheable(value = "roleService", key = "#roleId") @Override public RoleInfo findOne(Long l) { System.out.println("RoleServiceImpl.findOne"); RoleInfo one = this.mapper.findById(l).get(); return one; } // 这个key是重返回值中拿到插入之后的数据,是在redis中的缓存中拿到的 @CachePut(value = "roleService", key = "#roleInfo.roleId") @Override public RoleInfo addOne(RoleInfo roleInfo) { System.out.println("RoleServiceImpl.addOne"); RoleInfo save = this.mapper.save(roleInfo); return save; } // 清空所有缓存(卡死以为的,奥恩退思) @CacheEvict(value = "roleService", allEntries = true) @Override public Boolean delete(Long roleId) { System.out.println("RoleServiceImpl.delete"); this.mapper.deleteById(roleId); return true; } // 点赞demo public boolean thumb(Long roleId) { ZSetOperations<Object, Object> forZSet = this.redisTemplate.opsForZSet(); // 根据roleId查询信息. RoleInfo one = findOne(roleId); // 向redis缓存中缓存对象,每次刷新网页赞+1 forZSet.incrementScore("thumb:roleId", one, 1); return true; } public Set<?> thumbList() { ZSetOperations<Object, Object> opsForZSet = this.redisTemplate.opsForZSet(); // 根据key取出缓存中的数据,并排序,赞多的在前面. Set<ZSetOperations.TypedTuple<Object>> scores = opsForZSet.reverseRangeWithScores("thumb:roleId", 0, 2); return scores; } -
创建controller层,代码如下:
import com.lanou3g.springredis.RoleService.RoleService; import com.lanou3g.springredis.entity.RoleInfo; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import javax.annotation.Resource; import java.util.List; import java.util.Set; @RestController @RequestMapping("/role") public class RoleController { @Resource private RoleService roleService; @RequestMapping("/findAll") public List<RoleInfo> findAll() { List<RoleInfo> all = this.roleService.findAll(); System.out.println(all + "**********"); return all; } @RequestMapping("/findOne/{roleId}") public RoleInfo findOne(@PathVariable Long roleId) { RoleInfo one = this.roleService.findOne(roleId); return one; } @RequestMapping("/addOne") public Boolean addOne(RoleInfo roleInfo) { this.roleService.addOne(roleInfo); return true; } @RequestMapping("/delete/{roleId}") public Boolean delete(@PathVariable Long roleId) { return this.roleService.delete(roleId); } @RequestMapping("/like/{roleId}") public boolean like(@PathVariable Long roleId) { return this.roleService.thumb(roleId); } @RequestMapping("/thumbList") public Set<?> thumbList() { Set<?> set = this.roleService.thumbList(); return set; }}
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创建配置文件类,代码如下:
import com.fasterxml.jackson.databind.ObjectMapper; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.data.redis.connection.RedisConnectionFactory; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer; import java.text.SimpleDateFormat; @Configuration public class RedisConfig { @Bean public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory factory) { RedisTemplate<Object, Object> template = new RedisTemplate<>(); template.setConnectionFactory(factory); // 定制Jackson ObjectMapper mapper = new ObjectMapper(); mapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd hh:mm:ss")); Jackson2JsonRedisSerializer serializer = new Jackson2JsonRedisSerializer<Object>(Object.class); // 把value序列化成json格式. template.setValueSerializer(serializer); template.setKeySerializer(serializer); // 转json // 文件里的配置也会加载. template.afterPropertiesSet(); return template; } } -
application.yml配置文件如下:
spring:
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/netctoss
username: root
password: root
#最大活跃数
maxActive: 20
#初始化数量
initialSize: 1
#最大连接等待超时时间
maxWait: 60000
#打开PSCache，并且指定每个连接PSCache的大小
poolPreparedStatements: true
maxPoolPreparedStatementPerConnectionSize: 20
#通过connectionProperties属性来打开mergeSql功能；慢SQL记录
#connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
minIdle: 1
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 300000
validationQuery: select 1 from dual
testWhileIdle: true
testOnBorrow: false
testOnReturn: falsejpa:
show-sql: true
hibernate:
ddl-auto: none
jackson:
serialization:
indent_output: true
pom.xml配置如下:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/redis.clients/jedis -->
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.9.0</version>
</dependency>
三.效果如下
